I think that with the ion drive, the laws of celestial mechanics allow a bit more leeway than otherwise. That said, I'd rather move on to Ceres sooner rather than later -- that's a much larger and more interesting world. Of course, I'd also like to see real-time data releases :/

Yeah, Dawn's launch was delayed three months, but the ion drive gives so much leeway it didn't matter in the end (compared with a conventional launch to Mars for example, that has a very specific window).

There is always a tug downward, but because of Vesta's heterogeneous interior structure, the product of its complex geologic history, sometimes there is also a slight force to one side or another. With their knowledge of the gravity field, the team plotted a course that took advantage of these variations to get a free ride. This is akin to experienced sailors not only relying on their ships' engines but also following routes that use known currents to let nature do some of the work. Of course, sailors benefit from knowledge of currents measured by those who plied the waters before them. Dawn is the first, venturing boldly into mysterious seas never visited before. But the measurements of the gravity field in HAMO, even though it was at a higher altitude, gave navigators enough information about what lay ahead on the horizon that our vessel could safely and productively ride the gravitational currents. The flight plan from HAMO to LAMO then is a complex affair of carefully timed thrusting and equally carefully timed coasting. Under ion thrust, the spacecraft flies to a certain location in a certain orbit at a certain time, waits a certain interval as Vesta propels it to the next waypoint, and then it resumes thrusting.

Yeah, Dawn's launch was delayed three months, but the ion drive gives so much leeway it didn't matter in the end (compared with a conventional launch to Mars for example, that has a very specific window).

Supposedly that delay was running up against the window from Vesta to Ceres, so I suspect there may not be much more leeway to stay at Vesta. Perhaps someone who knows for sure will chime in.

"Russell: pole position for Vesta measured by Dawn differs from astronomically determined value. #AGU11 (1 hour ago)""Russrll: spring will return to dark north pole later than thought, so they will need to delay Vesta departure in order to image it. #AGU11 (1 hour ago)"

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